Final Report Summary - REFINE (Phenotypic plasticity, animal welfare, and the validity of animal experiments.)
Animal experiments are a notoriously controversial topic. However, most people are supportive of animal research if it is humane, scientifically sound, and likely to advance science or medicine. The project REFINE was initiated to contribute to this in two main ways, using mice as an example: (i) by studying which aspects of the living conditions of mice are important for their well-being, and (ii) how experiments can be designed in ways that increase the gain of knowledge and improve their reproducibility. We could show that space per mouse, which is the basis of all housing regulations, is not the critical factor but that the provision of key resources, group size, and social dynamics in the group are more important. Furthermore, we found that while simple enrichments such as nesting material and shelter can be beneficial for mouse welfare, more extensive forms of enrichment may be needed to attenuate the development of abnormal repetitive behaviour and other signs of poor welfare. Furthermore, we found that single-laboratory studies conducted under highly standardized conditions yield results of poor external validity, while studies involving as few as 2-4 laboratories yield results that are considerably more robust and better reproducible. This means that single-laboratory studies need to incorporate biological variation into the experimental design if they are to achieve a similar level of reproducibility. Taken together, REFINE has made significant contributions towards a scientific basis for effective refinement of animal housing and experimental design in view of improving both the scientific validity of animal experiments and the welfare of experimental animals.